Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG Engines

The FAA is adopting a new airworthiness directive (AD) for certain Rolls-Royce Deutschland Ltd & Co KG (RRD) Model Trent 1000-A, Trent 1000-AE, Trent 1000-C, Trent 1000-CE, Trent 1000-D, Trent 1000-E, Trent 1000-G, and Trent 1000-H engines. This AD was prompted by a determination made by the manufacturer that a high-pressure compressor (HPC) mini-disc anti-rotation block could possibly release into the HPC assembly stage 5 and 6 discs and the cone rotor rear shaft (HPC rear drum) during an engine operation. This AD requires repetitive borescope inspections (BSIs) of the HPC rear drum cavity and cavities between each HPC rotor disc, and depending on the results of inspection, removal of the engine from service. This AD also allows an alternative method of complying with the repetitive BSIs if certain actions are accomplished. The FAA is issuing this AD to address the unsafe condition on these products.